United Statesian vs Usonan

United Statesian

noun

  • An inhabitant or citizen of the United States of America. 

adj

  • Of or pertaining to the United States of America. 

Usonan

noun

  • An inhabitant of the United States 

How often have the words United Statesian and Usonan occurred in a corpus of books? (source: Google Ngram Viewer )